The specific aims of this research are to investigate thedeterminants of variations in race-specific neonatal mortality rates among counties of the United States in 1977. Factors that will be emphasized are the availability of obstetricians and gynecologists, the presence of neonatal intensive care units, and the impacts of a number of public policies and programs. These programs include, but are not limited to, Medicaid, maternal and infant care (M and I) projects, other Federally subsidized health care delivery organizations such as communiy health centers and children and youth projects, Federally subsidized family planning services for low-income women, and abortion reform. Estimates of the effects of the above factors will control for poverty, schooling levels, family income, and other basic determinants of neonatal mortality. Some attention will be paid to the potential mechamisms via which the public programs can affect neonatal mortality. In particular, their impacts on the incidence of high-risk births and the receipt of appropriate prenatal care will be studied. The aims will be implemented by conducting cross-sectional regression analyses of differences in race-specific neonatal mortaility rates among counties of the United States in 1977. This procedure capitalizes on variations inthe programs, health manpower, and units that deliver sophisticated neonatalogical ervices among counties at a moment in time. After estimating the regressions, we will apply their coefficients to national trends in the exogenous variables to "explain" the downward trent in neonatal mortality.